1. Field of the Invention
The present invention relates generally to a float switch, and more particularly to a float switch, which turned on or off the power according to the height of water level.
2. Description of the Related Art
As shown in FIG. 8, a conventional float switch, which floats on water of a tank, has a hollow main member 7, in which a chamber 74 is provided, and a wire 71 connected to a pump (not shown). The chamber 74 is divided into a first space 75 and a second space 76. A bob 73 is received in the chamber 74 to move between the first space 75 and the second space 76. A microswitch 77 is mounted in the first space 75 and is connected to the wire 71. The microswitch 77 has a spring (not shown) connected with a pushing device 78, whereby the bob 73 runs to the first space 75 and presses the pushing device 78 to activate the microswitch 77.
While the tank is filled with water, the main member 7 is upright to have the bob 73 running to the first space 75 and pressing the pushing device 78 to turn on the microswitch 77, as a result, the pump stops working. While the liquid level of water is lower, the main member 7 is up side down to have the bob 73 leaving the pushing device 78 and running to the second space 76 to turn on the microswitch 77 and to start the pump.
The power of the conventional float switch is the gravity, which drive the bob 73 running between the first space 75 and the second space 76, and the weight of the bob 73 presses the pushing device 78 to activate the microswitch 77. But, somehow, the bob 73 might not press the pushing device 78 stably because of the water level raising too fast or the waves on water that the microswitch 77 will dump between turn-on and turn-off repeatedly. It makes the power waste as well as damages the microswitch 77 and the pump.
In addition, the pushing device 78 has to be arranged beside the microswitch 77 because of the limitation of the microswitch 77 and a path of the bob 73. As a result, the main member 7 must has an efficient width that the size of the main member 7 is too greater for a narrow space.